Isotopes journey from medical waste to medical treatment

To produce actinium-227, the isotope used for an FDA-approved cancer treatment, the first step is to bombard targets of the radioisotope radium-226 in ORNL's High Flux Isotope Reactor (HFIR).

The problem? Radium, produced by the radioactive decay of uranium, is very hard to find and extremely difficult to work with.

But it was much more plentiful in the past.

After radium was discovered more than a century ago, humans hurried to find new uses for this element, lauding its supposed health benefits. They put it in toothpaste, hair creams and even foods.

And it was widely used to treat tumors directly. Until the late 1960s, radium was fashioned into various sizes and shapes of narrow sealed containers, then implanted into cancer to stop growth.

By the time the adverse health effects of these products were discovered, decades of such medical waste needed disposal.

Now, the Department of Energy is bringing it back to produce life-saving radioisotopes.

DOE's Office of Isotope R&D and Production (DOE IRP) has secured legacy medical devices from hospitals, medical, and research facilities worldwide, diverting them from radioactive waste landfills, to be used as a source of radium-226.

ORNL receives welded cans of radium-filled needles and tubes that were placed in and around tumors, as well as other radium-containing medical equipment that has been replaced by more modern - and safer − technology. The radium technicians retrieve from these objects is used to fabricate pellets that are then irradiated, ultimately yielding Ac-227, thorium-228 and thorium-229 - all in-demand radioisotopes with potential medical uses.

But retrieving that radium isn't an easy process.

Besides radium and barium, medical devices contain many other metal contaminants. Because they're radioactive, they must be handled in hot cells and other controlled environments, and batches can contain broken glass and sharp metal fragments.

ORNL technicians use a mechanical chopper to open the devices to expose radium. They're then vibrated in a bath of nitric acid and washed 10 or more times to make the radium accessible. Devices that weren't opened by the chopper, which is continually being improved, are fished out and re-chopped. A grinder makes the chopped fragments even smaller.

Then, a complex series of separations involve different chemicals to remove other contaminants. One of those, lead-210, used in geological dating and as a tracer, is saved for possible future use.

The journey from obsolete device to pure radium is long. However, every exacting step is justified by what comes next.

Demand for these isotopes is surging, outstripping supply and leaving cancer patients waiting. Purified radium-226 is the indispensable feedstock that makes it all possible. Irradiated in ORNL's High Flux Isotope Reactor, it yields actinium-227, the parent of the FDA-approved radium-223 and thorium-227 used in targeted alpha therapies. It supplies thorium-228 for Ra/Pb generators that deliver lead-212 directly to tumors. And it provides the high-purity targets needed to produce actinium-225 in cyclotrons, one of the most promising agents in the fight against metastatic cancers.

By rescuing radium from decades-old needles, tubes, and plaques that once sat in landfills, the Department of Energy is closing a critical supply gap that began more than a century ago. Yesterday's medical waste has become today's medical breakthrough, turning a hazardous legacy into precision weapons against cancer, one life-saving isotope at a time.

UT-Battelle manages ORNL for the Department of Energy's Office of Science, the single largest supporter of basic research in the physical sciences in the United States. The Office of Science is working to address some of the most pressing challenges of our time. For more information, please visit energy.gov/science.